This app was created to figure out when Google Play shows the "in app purchases" in the google play store.
StackOver Flow question.
Play Store Link
https://play.google.com/store/apps/details?id=com.flesh.questions.whendoesitshow
TLDR;
The "In-app Purchases" section in the Play Store shows as soon as you activate the Subscription in the Play console and have the Billing Library Dependency as a Dependency in your App on the Production track. Both must be true and the "In-App Purchases" will disappear if you remove the Dependecny from the app in the production track.
Full Answer in the Stackoverflow Question